Question: Simplify the following expression: $p = \dfrac{x}{2} + \dfrac{x}{9}$
Solution: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $2$ and $9$ $\lcm(2, 9) = 18$ $ p = \dfrac{9}{9} \cdot \dfrac{x}{2} + \dfrac{2}{2} \cdot \dfrac{x}{9} $ $p = \dfrac{9x}{18} + \dfrac{2x}{18}$ $p = \dfrac{9x +2x}{18}$ $p = \dfrac{11x}{18}$